According to court documents, Shannon Maureen Conley of Arvada, Colorado, wanted to marry a Tunisian militant, who had joined the ISIL, and then train ISIL militants “in U.S. military tactics.”

Conley had met the Tunisian militant over the Internet and had joined a military career exploration program in order to learn US military tactics and train ISIL militants in those tactics.

“Conley stated that she joined the U.S. Army Explorers to be trained in U.S. military tactics and in firearms," officials said in court documents.

She was arrested at Denver International Airport on April 8 as she was about to board the first of a series of flights that would take her to the Turkish border with Syria where she could join the militants.

Takfiri ISIL militants – a radical al-Qaeda offshoot that enjoys support from loyalists of Iraq’s former Baathist regime – have taken control of some parts of Syria and Iraq.

Last month, two Texans – Michael Todd Wolfe and Rahatul Ashikim Khan – were also arrested by federal authorities for “attempting to provide material support to terrorists” both within US borders and inside Syria.

While several reports, observers, and even some US officials including Sen. Rand Paul (R-Kentucky) have said the terrorist militants in Iraq and Syria have been funded, trained, and armed by Washington, US officials have repeatedly raised concerns about the threat posed by these militants to America.

On Sunday, US President Barack Obama said that “battle-hardened” Europeans who have joined the ISIL in Syria and Iraq pose a “serious threat” to the US as they “have a European passport” and “don't need visas to get into the United States.”

Meanwhile, on Wednesday, the US Department of Homeland Security ordered the enhancement of security measures at selected overseas airports with direct flights to the US, saying al-Qaeda-affiliated groups like the al-Nusra Front, an al-Qaeda offshoot which is fighting the Syrian government, are planning to bomb US-bound flights.